As the final big primaries approach Democrats Hilary Clinton and Barack Obama remain locked in a tight race, though many think that if Obama wins in two or even one of the three remaining big states he will effectively "earn" the nomination by making it very hard for Clinton to continue to claim she has more broad based support than Obama and very unlikely for her to exceed his popular vote totals.
Although Pennsylvania still appears likely to go to Clinton, Ohio is getting closer and Texas now appears to favor Obama.
March 4 will be a big day for both candidates. Big wins for Obama likely will mean the race is over, but more close races will probably keep Clinton in through the convention when a lot can happen quickly. For example if the Florida and Michigan delegates are seated, and if a majority of superdelegates switch to Clinton she could gain the nomination even after losing most of the states in the popular vote. Given the Democrats concerns in 2000 it's hard to know how all this will shake out. Disenfranchising voters has been a key Democratic criticism of Republicans yet this is exactly the penalty they extracted from Michigan and Florida for holding primaries early. On the other side of the coin is the fact that Superdelegates have far more voting power than regular people, leading many to consider this elitist politics.